Losing control of your to-do list? These task managers can keep you on track.

In today's over-scheduled society, a solid task-management app can help keep you on top of your to-do list -- and prevent last-minute panics. For example, it can help you meet milestones for a work-related project, or remind you while running errands that your dry cleaning is ready for pick-up.

Most task management apps work similarly, abiding by the "Getting Things Done" (GTD) principles of time management. First, you create a new "task" by briefly describing it. You can then add notes, assign a deadline for its completion, designate its priority level, organize it into a folder or list category (e.g., "personal errands," "work duties") and set an alarm to remind you about it on a certain date and time.

In this manner, you build a sequential order of to-do's. When you complete a task, you mark it as finished; depending on the app in question, this could be done swiping across it, or tapping a box by the task to mark it with a check or "X."

This task manager sports a bright, airy blue and white design that emphasizes white space and large, readable fonts. Its overall look is easy on the eyes and fits the smartphone format well. (The theme can be flipped to an inverted version, with white text set against black.)

You add a new task by tapping the entry box at the top of the screen and then inputting your text. Tap on a task and a toolbar will slide open below it; you can then mark the task as urgent, move it to another folder, set an alarm to alert you about it on a specified day and time, add a note to it, or forward it to someone in your contacts book as an email or Facebook message.

You can reorder your tasks by pressing on a task and dragging it to another place on the list. I found this easy and fast to do, even when I held the phone with one hand and used my thumb to move them around.

A "shake to clear" function lets you shake your device to clear your list of tasks that you've marked as finished. I'm not too fond of this (I personally feel most shake functions on smartphone apps are gimmicky), but it does fit with the one-hand operation approach of Any.DO.

You can sync your task lists with any other devices that also have the Any.DO app installed by signing up for a free account on the Any.DO site. You can also sync your Any.DO lists with your Google account to use with Google Tasks.

Bottom line:

Any.DO has a simple, easy-to-read interface and allows you to effortlessly create, edit and adjust your task list.

The entry box for entering a new task is set at the bottom of the main screen. Two buttons below that labeled "Who" and "When" let you choose people from your contacts to assign to the task (and allows them to collaborate with you on it) and designate a deadline.

Tap on an existing task and you're taken to an "Edit Task" screen that lists details such as deadline, a log of changes and progress, and people attached to it. You can also set an alert, add notes and rate its importance (using three levels). You can even add an image (snapped from your device's camera or one already saved on it).

Press and hold on a task to copy or delete it -- and like Any.DO, Astrid lets you drag it to another place on the list. But first you have to set it to do so by tapping the lists icon (or alternately your Android device's settings button), tapping Sort & Subtasks, then choosing "Drag & Drop with Subtasks" as the way you want to sort the order of your lists.

However, Astrid includes a useful function few other apps do: Timer controls let you input how long (in hours and minutes) a task should take to complete, and how much time has already been spent on it. In addition, there's a stopwatch tool on the Edit Task page. Tap it when you start your task, and tap it again when you've stopped working; Astrid will log how much time you spent on it. Very handy, especially for contractors who charge by the hour.

You can sync your task lists with other devices running Astrid by setting up a free account on astrid.com. And like Any.DO, your Astrid task lists can be synced with Google Tasks.

Bottom line

Astrid is obviously well suited for multiple users who need to collaborate. It's a good task manager, beating Any.DO in the number of features. But unless you need its timer tool, it may be overkill when you don't need to share your tasks with others.